JPS58202440A - Ultraviolet-curing composition for filling hole - Google Patents

Abstract

PURPOSE:To obtain an ultraviolet-curing composition for filling holes with superior ultraviolet-curability, through hole protecting power and alkali removability, by mixing a satd. org. compound having a specified acid value with a monoester compound and a photosensitizer. CONSTITUTION:A satd. org. compound (A) having >=60 deg.C softening point and 50-500 acid value such as phthalic anhydride is mixed with a monoester compound (B) represented by formula I , II or III (where R is H or methyl, R' is H or 1-4C alkyl, and Y is a bivalent org. group) and a photosensitizer (C) such as benzoin to obtain the desired ultraviolet-curing composition for filling holes. In order to temporarily protet plating in through-holes in a both-side printed wiring substrate from etching during pattern formation, the composition is filled into the holes, cured with ultraviolet rays, and removed with an aqueous alkali soln. after finishing etching.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ultraviolet curable pore-filling composition used to temporarily protect a mesh layer from etching during pattern formation.

In recent years, the integration of electrical components has progressed, and the use of double-sided printed wiring boards in which conductive patterns are formed on the front and back sides of printed wiring boards has increased.

Conventionally, the method for manufacturing the above-mentioned double-sided printed wiring board is as follows:
First, holes for through-poles are drilled at desired locations on the double-sided copper-clad laminate, and a conductive layer is formed in these holes using the through-hole method to form through-holes for electrically connecting the conductor patterns on the front and back sides. Next, a thermosetting hole-filling ink is filled into the through hole, and the hole-filling ink is heated and cured.

After that, form the required pattern with acid-resistant ink on the front and back sides of the laminated board, and after curing the acid-resistant ink,
Esotics are removed using an acidic esotinic solution such as cupric chloride or ferric chloride. A double-sided printed wiring board is prepared by removing the hole-filling ink and the acid-resistant ink using an alkaline aqueous solution.

Various types of thermosetting hole-filling inks have been studied to be used in the processing step described in -1- above, but generally the time required for thermosetting is long. In addition, the volumetric shrinkage caused by the evaporation of the solvent contained therein makes the protective effect of the through-hole edge portion insufficient, and that portion is etched during etching, resulting in a decrease in the performance of the printed wiring board.
Furthermore, the removability of the hole-filling ink using an alkaline aqueous solution is poor, and it remains attached to the inner wall of the through-hole, causing trouble when installing components, and the required performance has not been fully satisfied.

An object of the present invention is to provide an ultraviolet-cured hole-filling composition that is cured by ultraviolet light in a short time, has excellent through-hole protection properties, and is easily removed by an aqueous alkaline solution.

The UV-cured pore-filling composition of the present invention comprises (A) a saturated organic compound having a softening point of 60°C or higher and a 1-1 acid value of 50 to 500; (13) a compound having the general formula (+), (II) or (11); A monoester compound represented by Saka [in the formula, R is hydrogen or a methyl group, R' is hydrogen or an alkyl group having 1 to 4 carbon atoms, and Y is a divalent organic group], and (to) a sensitizer. It consists of a drug.

Examples of saturated compounds having a softening point of 60° C. or higher and an acid value of 50 to 500 used as component (A) of the composition according to the present invention include polybasic acids such as phthalic anhydride, isophthalic acid, Terephthalic acid, adipic acid, sehananic acid,
Tetrahydrophthalic acid, I\GIL hydrophthalic acid, het acid, hemic acid, trimellitic acid, bimellitic acid, polyhydric glycols, e.g. evaethylene glycol, polyethylene glycol, furopylene gellicol, Horipropylene chloride, 1,3-butol, 1゜4-
Butanediol, l,6-hexanediol, unionic licorice, trimethylolethane, trimethylol fluorine, pentaerythritol natoto carboxyl group-containing polyester resin, rosin-modified maleic acid resin, rosin-modified phenol resin , polymerized rosin, hydrogenated rosin, and carboxyl group-containing petroleum resin.

These saturated organic compounds may be used alone or in combination of two or more in any proportion. The softening point of these saturated organic compounds is 60°C or higher, preferably 80°C or higher.
If the softening point is below 60° C., the protective effect of the through-hole will be reduced due to the softening of the ultraviolet-cured composition during notching. In addition, the acid value of these compounds is 50 to 500.
, preferably 100-400. If the acid value is less than 50, the removability with an aqueous -norkali solution decreases, and the acid value is less than 50.
If it is less than 0, the resistance to the esotynde liquid decreases, and the moisturizing effect of the through hole during esotinction is reduced. or (Ill) 1, where R is hydrogen or a methyl group, It' is hydrogen or an alkyl group having 1 to 4 carbon atoms, and Y is a divalent group, preferably an alkylene group having 1 to 4 carbon atoms. Or - (CnH,, falsification), -
CI, , - group, (n is 2 to 6, q is an integer of 1 to 19)] Examples of mononisder compounds represented by a) are as follows. Sunao) also contains phthalic acid, tetrahydrophthalic acid, 3
-Methyltetrahydrophthalic acid, 4-methyldetrahydrophthalic acid, 3-ethyltetrahydrophthalic acid, 4-ethyltetrahydrophthalic acid, 3-propyltetrahydrophthalic acid, 4-propyltetrahydrophthalic acid, 3-butyltetrahydrophthalic acid, 4-Butyltetrahydrophthalic acid, \xahydrophthalic acid, 3-methylhexahydrophthalic acid, 4-methylhexahydrophthalic acid, 3-
Ethyl hexahydrophthalic acid, 4-ethyl hexahydrophthalic anhydride, 3-propyl hexahydrophthalic acid,
Examples include 4-propylhexahydrophthalic acid, 3-butylhexahydrophthalic acid, and 4-butylhequinahydrophthalic acid.

Among these, particularly preferred are phthalic acid/tetonohyl fucuric acid, 3-menal f trahydrofucric acid, 4
-Methyltetrahydrofucric acid, hexyldi1゛[jphthalic acid, 3-methylhexahydrophthalic acid, 4-methylhexahydrophthalic acid.

The alcohol components constituting the above monoester compound include 2-hydroxyethyl (meth)acrylate, 2
-Hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, polybutylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, polybutylene glycol mono(meth)acrylate, polycaprolactone mono(meth)acrylate Examples include stoichiometric substances such as acrylates.

The monoester compound described in 1-1 may be used alone or in combinations of two or more.
- can also be used at any rate.

The synthesis of the monoester compounds listed above is preferably carried out by a ring-opening addition reaction between the anhydride of the above acid and the Vt compound listed above, but it may also be synthesized by a conventional esterification reaction. can. In the synthesis of the above-mentioned monoesterified compound, it is preferable to use 1 mol of the soft form of the 1-2 acid per 1 mol of the anhydride of the 1-2 acid, but one may be used in excess. In the addition reaction, the reaction 7 crystallinity is usually 50 to 150°C, particularly preferably 80 to 11°C.
It is 0°C. Further, as a reaction accelerator, tertiary amines such as triethylamine, morpholine, triethanolamine, pentamethyldiethylenet'I-J-mino, or their quaternary ammonium salts can be used.
In order to prevent polymerization during the reaction, a polymerization inhibitor such as hydroquinone, hydroquinone monomethyl ether, t-butylhydroquinone, t-j thylcatechol, benzoquinone, fetchacin, etc. may be used [7].

The reaction progress of the ring-opening addition reaction can be easily determined from the infrared absorption spectrum of the acid anhydride, and the reaction may be considered to have substantially completed when the infrared absorption spectrum peak of the acid anhydride disappears.

The photosensitizer used as component (C) of the composition according to the present invention may be any known photosensitizer, but is required to have good storage stability after blending. Examples of such photosensitizers include: 2,2
-diethoquinono'cetophenone, 4'-phenoxy-
Acetophenone photosensitizers such as 2,2 dichloroacetophenone, propiophenone photosensitizers such as 2-hydroxy 2-methylpropiophenone, and 4'-isopropyl-2-hydroxy-2-methylpropiophenone. anthra-1-non photosensitizers such as 2-ethylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, and 2-amylanthraquinone;
Examples include thioxanthone sensitizers such as 2-chlorothioxanthone and 2-butylthioxanthone. These photosensitizers can be used alone or in combination of two or more in any ratio.

The amount of component (A) used in the composition according to the invention is preferably 10 to 70% by weight of the composition, particularly preferably 1
It is 5 to 60% by weight. If the amount of component (A) is less than 10% by weight, the removability of the composition described in 1-1 with an alkaline aqueous solution will decrease, and if it is more than 70% by weight, the viscosity will increase, making it difficult to fill the composition into the through hole. becomes. component(
The amount of B) is preferably 30 to 90% by weight of the composition;
Particularly preferably 40 to 80% by weight. If the amount of component (B) is less than 30% by weight, the curability by ultraviolet rays will be reduced, and if it is more than 90% by weight, the removability of the composition with an aqueous alkaline solution will be reduced. The amount of component (C) is preferably 0.5 to 20% by weight of the composition, particularly preferably 1
．． It is 5 to 15% by weight. If component (C) is less than 0.5% by weight, the curability by ultraviolet rays will be markedly reduced, and if it is more than 20% by weight, the etching resistance will be reduced.

The composition according to the invention may further contain unsaturated compounds other than the monoester compounds of component (B).

Examples of such unsaturated compounds include 2-hydroxyethyl (meth)acrylate, 2-hy-1-, roquinbrovir (meth)acryle-1-, cellosolve (meth)acrylate, methylcelonorb (meth)acrylate,
Butyl cellosolol (meth)acrylate, carpitol (meth)acrylate, methylcarpitol (meth)
Acrylate, butylcarpitol (meth)acrylate
, -1-, phenoxyethyl (meth)acrylate-1-noclopentadienyl (meth)acrylate, cyclopentadienyloxyethyl (meth)acrylate, vinyl acetate, N, -vinylpyrrolidone, -j trahydrofur Furyl (meth)acrylate, polyethylene glycol mono(meth)acrylate/polypropylene glycol mono(meth)acrylate, polybunalene glycol mono(meth)acrylate, polycaprolactone mono(
Scientifically functional unsaturated compounds such as meth)acrylate, phenylglycine ether (meth)acrylic acid adducts, polyethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate , polycaprolactone di(meth)acrylate, 1,6 hexanediol di(meth)7'acrylate, and difunctional unsaturated compounds such as inopentyl glycol di(meth)acrylate. If more than 50% by weight is used, removability with an alkaline aqueous solution will be reduced, which is not preferable.

The composition according to the present invention further includes:
Extender pigments, antifoaming agents, coloring pigments, thixotropic agents, etc. can be added as appropriate.

In practical use, the composition according to the present invention is first filled into the through holes of a double-sided copper-clad laminate plated with through holes. The filling methods include a dipping filling method in which the laminate is immersed in the composition, a roll filling method in which the laminate is passed between sponge rolls filled with the composition, and a method in which the laminate is attached to a pin. Examples include filling pins into through holes. If an excessive amount of the composition adheres to the surface of the laminate during the filling process, it may be scraped off with a squeegee such as a urethane comb or a squeegee or a metal plate.

Next, both surfaces of the laminate filled with the composition are irradiated with ultraviolet rays. Irradiation of ultraviolet rays may be carried out on one side at a time or on both sides at the same time. UV irradiation is usually 50 to 200
Using a high-pressure mercury lamp or a metal halide lamp, a short time of 30 seconds or less is sufficient, and curing can be completed by such irradiation.

After curing with ultraviolet rays, if there is a large amount of the ultraviolet-cured composition remaining on both surfaces of the laminate, mechanical polishing using a flannel or the like may be performed. Thereafter, acid-resistant ink is printed on both sides of the laminate by screen printing, offset printing, etc. to form the desired backing. After curing the acid-resistant ink, the exposed copper portion is removed by etching with an acidic etching solution such as ferric chloride or cupric chloride. Finally, the acid-resistant ink and the above composition are removed using an alkaline aqueous solution to produce a double-sided printed wiring board.

The ultraviolet-curable pore-filling composition of the present invention can be cured by short-term irradiation with ultraviolet light. In addition, this one-component product has excellent protection against etching of through-holes, and is easily removed by an alkaline aqueous solution, making it extremely suitable as a composition for filling through-holes in double-sided printed wiring boards. Examples of the present invention are shown below.

Example 1 Ethylene glycol 248F (4 mol) 1 isofucric acid 1669 (3 mol), trimellitic anhydride 192f (1
mol) in a flask equipped with a stirrer, and stirred at 190°C.
A saturated compound (A-1) was obtained by carrying out a time esterification reaction. This compound had an acid value of 170 and a softening point of 72°C.

Phthalic anhydride l.189 (1 mol) and 2-hydroquine ethyl acrylate 1169 (1 mol) were placed in a flask equipped with a stirring device and reacted at 95°C for 8 hours until the peak of the acid anhydride in the infrared absorption spectrum disappeared. Monoester compound (B-1) was obtained: 15 parts by weight of the above (A-1), 80 East Section of the above (B-1), 4 parts by weight of hendiine isobutyl ether as a photosensitizer, 2-ethyl 1 part by weight of anthraquinone, 20 parts by weight of talc, 2 parts by weight of Elonlu, and 0.5 parts by weight of Fucron γ-Nbrun were blended to obtain an ultraviolet-curable hole-filling composition.

A double-sided copper-clad laminate with through holes formed therein is immersed in the above composition, and after the through holes are filled with the composition, it is taken out and the composition adhered to both sides of the laminate is scraped off with a urethane squeegee. After removing it, it was cured by irradiating it with ultraviolet light from both sides.

A 120°C metal halide lamp was used as the ultraviolet lamp, and the irradiation time was 8 seconds. After curing the composition with ultraviolet rays, both sides of the laminate were lightly polished with a brush, and acid-resistant ink MT-11V 5106 (
(manufactured by Mitsui Toatsusha) was printed and cured. The exposed copper portion was etched away using cupric chloride etching solution at 50°C, and after washing with water, it was etched at 40°C for 30 minutes.
% sodium hydroxide aqueous solution to remove the above composition and acid-resistant ink to prepare a double-sided printed wiring dam board.

The time required for removal with the sodium hydroxide aqueous solution was 30 seconds, and no etching occurred on the through-holes, and there was no deterioration in the performance of the through-holes.Example 2 4-Methyltetrahydrophthalic anhydride 166f (1 mol), 2-hydroxyethyl methacrylate l 3
A monoester compound (B-2) was obtained by reacting 0 r (t mol) in the same manner as in Example 1. As a saturated compound (A-2), the acid value was 350 and the softening point was 150.
50 parts by weight of rosin-modified-l oleic acid resin at
-2) as a photosensitizer, 35 parts by weight of 2-hydroxy-
14 parts by weight of 2-methylpropiophenone; 710 parts by weight of chlorine, 10 parts by weight of silium sulfate, 4 parts by weight of Bμ phthalocyanine blue, and 1 part by weight of Bμ phthalocyanine blue were blended to improve filling properties into the through holes. A sponge roll was impregnated with the above composition, and a double-sided copper-clad laminate with through threads formed between the rolls was placed in one place, and the above composition was applied into the through holes. The composition described in (1) adhering to both sides of the filled laminate was scraped off with a brass blade, and then cured by irradiation with ultraviolet rays.120 W/.

Using a high-pressure mercury lamp, each side was irradiated with ultraviolet light. The total irradiation time was 20 seconds. Then, Example 1
Similarly, the acid-resistant ink was printed and cured, and etched with a ferric chloride etching solution at 50°C.The above composition and acid-resistant ink were removed with a 3% sodium hydroxide aqueous solution at 040°C to form a double-sided printed wiring board. Created. The time required for the removal with the sodium hydroxide aqueous solution was 25 seconds, the through holes were not etched, and there was no deterioration in the performance of the through holes.

Example 3 ・1xahydrophthalic anhydride 1549 (1 mol), 2
was reacted with 1.u xypropyl methacrylate (1 mol) in the same manner as in Example 1 to obtain a monoester compound (B-3). As a saturated compound (A-3), the acid value was 1.
40, hydrogenated [con/con 30 parts by weight with a softening point of 70°C, the above (
B-3) - 10-layered wall part, 8-fold walled part as a photosensitizer, 22 parts by weight of 2-hytroquinethyl methacrylate as other unsaturated compounds, to improve filling properties into through-holes. A UV-cured hole-filling composition was obtained by blending 10 parts by weight of Taruri, 5 parts by weight of carbonic acid, and 0.5 parts by weight of phthalocyanine blue. The composition was inserted into the through-holes of a double-sided copper-clad laminate with through-holes formed thereon, and the composition described above was filled in the through-holes, and then ultraviolet rays were irradiated from both sides to cure the composition. A high pressure mercury lamp of 80 W/ was used, and the irradiation time was 12 seconds. After that, acid-resistant ink was printed and cured in the same manner as in Example 1, and the temperature was 50°C.
The exposed parts of the copper were etched away using a second hand etching liquid, and after washing with water, the above composition and acid-resistant ink were removed with a 3% sodium hydroxide aqueous solution at 40°C to form a double-sided printed wiring board. It took 25 seconds to remove the 1-hydrogen oxide solution using an aqueous sodium oxide solution, and there was no deterioration in the performance of the through-holes, which would otherwise occur due to etching of the through-holes.

Example 4 4-methylhexahydrofucric anhydride 168y (t mol), 2-hydroxypropyl acrylate 130r (
1 mol) and 0.32 mol of hydroquinone were reacted in the same manner as in Example 1 to obtain a monoester compound (B-4).

As a saturated compound (A-4), acid value 150, softening point 90°C
20 parts by weight of polymerized rosin, the above (B-4) 50i hard part,
As a photosensitizer, 13 parts by weight of 4'-phenoxy-2゜2dic [coacetophenone], as other unsaturated compounds, 17 parts by weight of tetrahydrofurfurylmethac II, and barium sulfate to improve through-hole filling properties. 15
parts by weight, 3 parts by weight of a montmorillonite thixotropic agent, and 0.5 parts by weight of phthalocyanine blue to obtain a composition for filling ultraviolet pores.

1- The composition described above was filled into the through hole by the dipping method in the same manner as in Example 1, and was cured by irradiating ultraviolet rays from both sides.

After curing the above composition with ultraviolet rays (120 W/n high-pressure water lamp) and irradiation time of 8 seconds, both sides of the laminate were polished and acid-resistant ink was applied. was printed, cured, and then etched using a ferric chloride etching solution at 50°C. 3 at 40℃
The above composition and the acid-resistant ink were removed using a 1-lium hydroxide aqueous solution to prepare a double-sided printed acid ray board.

There was no deterioration in the performance of the through hole.
Human Oxyethyl acrylate 116 (1 mol) and hydroquinone 0.32 were reacted in the same manner as in Example 1 to obtain a monoester compound (E-5). Saturated compounds (
40 parts by weight of (A-1) obtained in Example 1 as A-4), 20 parts by weight of (11-5) as a monoester compound, 20 parts by weight of (H-1) obtained in Example 1i, As a photosensitizer, C2hiI・Rokino 2-methylso[
Copiofuenon 5 City Nyubu・2-ri°″Chioki+7to'/
2 parts by weight, 3 parts by weight of 2-ethylanthraquinone, 10 parts by weight of cellosolve acrylate as other unsaturated compounds, and 9 parts by weight to improve filling properties into through holes.
20 parts by weight, 2 parts by weight of Koji Ojil, Phthalocyanipple
0.5 parts by weight was blended to obtain an ultraviolet-curable pore-filling composition.

The composition described above was filled into the through hole in the same manner as in Example 3, and was cured by irradiating ultraviolet rays from both sides.

A +20 W/metal halide lamp was used, and the irradiation time was 9 seconds. Thereafter, as in Example 1, acid-resistant ink was printed and cured, and the exposed copper portion was removed by etching with a 50°C ferric chloride etching solution. After washing with water,
The above composition and the acid-resistant ink were removed using a 3% sodium trihydroxide 7 solution at °C to produce a double-sided printed wiring board. The time required for removal using the IJ UNO aqueous solution was 20 seconds, no etching of the through holes occurred, and there was no deterioration in the performance of the through holes.

Example 6 Noethylene glycol 371? (3.5 mol), hydrogenated hisphenol A2409 (1 mol), tetrahydrophthalic anhydride 152F (1 mol), inophthalic anhydride 71332F (2 mol), trimellitic anhydride 96 f
(0.5 mol) in a flask with a stirrer and heated to 200°C.
The esterification reaction was carried out for 12 hours at
-6) was obtained. The acid value of this compound is 215 and the softening point is 9.
The temperature was 1°C.

3-methyltetrahytomipthalic anhydride 166 (1 mol), tetraethylene glycol monoacrylate 358
F (1 mol), hydroquinone 0. The reaction mixture was reacted in the same manner as in Example 1 to obtain a monoester compound (B-6). 35 parts by weight of the above (A-6), the above (B-6)
20 parts by weight, (B-1) 19 obtained in Example 1
parts by weight, and 73 parts by weight of 2,2-jethoxyacetophenol as a photosensitizer, 3 parts by weight of 2-diOcyanthraquinone, and N-vinyl vinyl as other unsaturated compounds.
20 parts by weight of J Ridon, 720 parts by weight of Tsuru to improve filling properties into through holes, and 1 part by weight of Elonlu were blended to obtain an ultraviolet-curable hole-filling composition. Example 2 The above composition
Fill the through hole using the roll filling method in the same way as
It was cured by irradiating ultraviolet rays from both sides. The ultraviolet lamp uses a 120W/crn high-pressure mercury lamp, and the irradiation time is 1.
It was 0 seconds. Thereafter, the acid-resistant ink was printed and cured in the same manner as in Example 1, and etching was performed using a ferric chloride etching solution at 50°C. The above composition and acid-resistant ink were removed from a 3% aqueous sodium hydroxide solution at 40°C to produce a double-sided printed wiring board. The time required for removal using the aqueous solution of thorium hydroxide was 23 seconds, and there was no esotinking of the through holes and no deterioration in the performance of the through holes.

Example 7: Methyl \xahydrofucric anhydride 168f (
Monoester compound (11-7) was obtained by reacting 0.59 mol of hydroquinone in the same manner as in Example 1. 20 parts by weight of (A-6) obtained in Example 6, '(
20 parts by weight of (A-2) used in Example 2, 13 parts by weight of (B-7), 2-human [
8 parts by weight of 2-methylpropiophenone, 2-]-
4 parts by weight of tylanthraquine, 5 parts by weight of tripropylene glycol diacrylate as other unsaturated compounds, 10 parts by weight of calcium carbonate, and 1 part by weight of hydrogenated castor oil to improve filling properties into through holes. A UV-cured pore-filling composition was obtained. The above composition was filled into the through hole in the same manner as in Example 3, and was cured by irradiating ultraviolet rays from both sides. A 120 W/metal halide lamp was used, and the irradiation time was 10 seconds. Thereafter, acid-resistant ink was printed and cured in the same manner as in Example 1, and the exposed copper portion was etched with a ferric chloride etching solution at 50°C, and after washing with water, 13% hydroxide was applied at 40°C.
The above composition and acid-resistant ink were removed from the J Uno aqueous solution to prepare a double-sided printed wiring board.The time required to remove the sodium oxide aqueous solution was 25 seconds.
There was no eso-tink to the through-hole, and there was no deterioration in the through-hole performance.

Claims (1)

[Claims] (11(A) Softening point is 60°C or higher, acid value is 50-500
A saturated organic compound of (13) general formula (1), (II) or (III) [wherein, It is aqueous or a methyl group, R' is hydrogen or an alkyl group having 1 to 4 carbon atoms, and Y is a divalent An ultraviolet-curable pore-filling composition comprising a monoester compound represented by the following organic group and a photosensitizer ((:).